| dc.description.abstract |
Because the rock mass is often accompanied by the joint, the overall shear strength of the rock mass is affected not only by the strength of the material itself, but also by the existence of the joint. The influence of the existence of rock joints on the shear strength of rock mass has been proposed by Barton to estimate the shear strength of rock mass under the influence of joint. Where the joint surface roughness is an important influencing factor, and the joint roughness coefficient (JRC) is usually used to represent the roughness of the section.
Barton (1977) proposed the visual comparison method for the earliest assessment of the JRC method, but because of this approach is more subjective, in recent years, many scholars have proposed numerical quantitative objective way to assess JRC. Due to different theories or assumptions in the assessment of JRC will cause some overestimation or underestimation, in this study, 86 rock joint sections (known as JRC) were collected and digitized and analyzed statistically. It is found that the elevation difference of the joint surface is normal distribution, and the standard deviation of the elevation difference is highly correlated with the JRC value. In this study, a new set of new rock joint sections was generated by the above parameters and use different JRC evaluation method for JRC calculation and comparison, and finally the JRC assessment of the distribution of the value of the trend of the proposed recommendations.
In addition, we use the PFC2D to simulate the unconfined compression test of rock and the basic friction angle of rock joint direct shear test After obtaining the rock mechanics parameters of this model, the numerical model of the direct shear test was established for one of the randomly generated rock joint and the standard profile proposed by Barton. The results obtained by this numerical model are compared with the empirical formula of shear strength proposed by Barton (1977). The results show that the shear mechanics behavior of the randomly generated joints is in accordance with the Barton standard profile and the empirical formula. | en_US |